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Elizabeth A. Lenton, Rafida Sulaiman, O. Sobowale and I. D. Cooke

Summary. Hormonal profiles were obtained throughout 26 conception cycles and 27 non-conception control cycles. The pregnancies followed treatment (clomiphene or bromocriptine) in 12 women but were spontaneous in the remaining 14. No sustained significant difference between the various types of conception cycle was found for LH, FSH, oestradiol or progesterone concentrations. Prolactin concentrations varied widely, suggesting that mean cycle prolactin concentrations ranging from 45 to 760 mi.u./l are compatible with conception. Although there were no significant differences in progesterone secretion within the conception cycles, there were highly significant differences between the conception cycles and the non-pregnant control cycles. Mean progesterone concentrations in the conception group were higher (P < 0·005) than those in the control women over Days 3–8 following the LH peak. This difference could only be partly accounted for by heterogeneity within the control group (15–20% of the control cycles had low progesterone concentrations and were probably subfertile). It is suggested that the higher conception cycle progesterone concentrations during the early part of the luteal phase may constitute a preimplantation component of the maternal recognition of pregnancy in women.

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Carol Lambadarios, Cetra Hastings, J. Abo-Darub and I. D. Cooke

Summary.

Human endometrium from the secretory phase of the menstrual cycle was incubated with 3H- and 14C-labelled glucosamine and [3H]leucine. Incorporation into secreted extracellular glycoprotein and accumulation of the label into the microsomal fraction were measured. When oestradiol or progesterone were added to the medium, medroxyprogesterone acetate (MPA), ethynodiol diacetate and chlormadinone acetate reduced incorporation of glucosamine and MPA reduced incorporation of leucine into glycoprotein. MPA reduced the amount of glucosamine in the microsomal fraction and also had an effect on amino acid transport within the endometrial cells, as indicated by intracellular μ-aminoisobutyric acid space measurements. These results and the ratios of 3H and 14C in the microsomal fraction and secreted protein suggest that MPA has a primary effect in decreasing amino sugar incorporation and a secondary effect in reducing amino acid incorporation into glycoprotein.

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S. K. Smith, Elizabeth A. Lenton and I. D. Cooke

Summary. Daily plasma concentrations of FSH, LH, oestradiol-17β and progesterone were compared for 12 cycles with a short luteal phase and 19 cycles with a luteal phase of normal length (i.e. cycles in which the luteal phase lasted 12 or more days). FSH and LH concentrations were suppressed in short luteal-phase cycles in the early follicular phase and the length of the follicular phase was prolonged (median duration, 14·5 days, range 13–21 days: compared with 12 days, range 9–17, in control cycles; P < 0·025). Preovulatory oestradiol-17β values and the mid-cycle concentrations of FSH and LH were similar in both groups. Plasma progesterone values in the luteal phase were similar in both groups over the 2nd to 5th days inclusive after the midcycle LH peak but declined in the short luteal phases thereafter. In short luteal-phase cycles, menstruation occurred in the presence of higher levels of oestradiol-17β and progesterone than in cycles of normal length and the rise of gonadotrophin in the late luteal phase of the cycle was delayed. These findings suggest that in cycles with a short luteal phase there is a lack of synchrony between the ovarian and menstrual events.

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I. D. Cooke, Elizabeth A. Lenton, M. Adams, Marianne A. Pearce, Diana Fahmy and C. R. Evans

The defective luteal phase

In the past 15 years the treatment of infertility has been affected most by progress in the induction of ovulation (Gemzell, Diczfalusy & Tillinger, 1958; Lunenfeld, Menzi & Volet, 1960; Kistner, 1975). The impact of this therapeutic advance is reflected in the diagnoses made during attendance at specialized clinics, as described by Cox (1975) and shown in Table 1, but there is still a large proportion of all patients (17·6% in Cox's study) in whom no cause can be found for their infertility.

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E. Kessopoulou, M. J. Tomlinson, C. L. R. Barratt, A. E. Bolton and I. D. Cooke

Summary. Peroxidative damage induced by reactive oxygen species (ROS) has been proposed as one of the major causes of defective sperm function. In previous studies of the production of ROS in semen, the contribution of contaminating leucocytes was not assessed. We determined the levels of ROS in 60 semen samples from men attending our infertility clinic and demonstrated by performing extraction experiments with antibody-coated magnetic beads that, within this unselected population of patients, leucocytes were the major source of ROS in the low-density Percoll fraction. Of the sperm motion parameters examined using computerized semen analysis, beat-cross frequency was the only one significantly affected by the ROS in semen.

Keywords: antibody-coated magnetic beads; computerized sperm motility analysis; leucocytes; reactive oxygen species; spermatozoa; human

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T. C. Li, M. A. Warren, P. Dockery and I. D. Cooke

Department of Obstetrics and Gynaecology, University of Sheffield, Jessop Hospital for Women, Sheffield S3 7RE, UK, and Department of Biomedicai Science, University of Sheffield, Sheffield S10 2TN, UK

Introduction

Grosser (1910) stated that the most important physiological function of the endometrial cycle is the preparation for the reception of a fertilized ovum (implantation), while menstruation is only a secondary process, a degeneration of the 'mucus membrane' which has not been able to fulfil its purpose. From the earlier work of Hertig et al. (1956), it is thought that implantation starts ∼6 days after ovulation. Croxatto et al. (1978) found that, in the natural cycle, the human embryo usually arrives in the endometrial cavity 96 h or more after the luteinizing hormone (LH) surge. In most in-vitro fertilization programmes, fertilized embryos are transferred to the endometrial cavity a day or two earlier, which is still compatible with successful implantation.

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E. A. Lenton, H. King, E. J. Thomas, S. K. Smith, R. I. McLachlan, S. MacNeil and I. D. Cooke

Follicular fluid is a unique body fluid containing a large number of biochemical components, some in extremely high concentrations, whilst in the middle of this relatively isolated biological compartment lies the arrested oocyte awaiting the signals to resume meiosis and progress towards timely ovulation. Delineation of these signals poses a challenging task. While there have been numerous reports on the concentrations of various steroids and peptides in follicular fluid after both natural and stimulated follicular growth and, similarly, the relationship between various components of oocyte maturation and the perceived signal has been studied in depth, the precise chronology of the endocrine changes relative to the sequence of oocyte maturation has not been systematically evaluated. Ideally the changing endocrine profile of the late preovulatory follicle would be best investigated by repeated frequent sampling (say every 2 h) of a single follicle. Unfortunately in the human such a longitudinal study would be difficult and so as an alternative approach we have considered the pattern of simultaneous endocrine changes in a cross-sectional group of follicles timed with respect to a common event (the start of the endogenous LH surge). The study of human follicular fluid is relatively simple because of the large volumes (2-8 ml) present in a preovulatory follicle but precise timing of the endogenous LH surge is more difficult due to the problems of frequent blood sampling. An alternative although slightly less precise method is to measure LH in frequent urine collections.